The Assiniboine & Sioux Tribes of the Fort Peck Reservation are going to build the Buffalo Rivers Casino and Lodge in Poplar, Montana. The project is now underway since funding approval has been provided. The casino is to be located in Poplar, Montana and open for operations by May 2016. In May 2015 a ground blessing ceremony is set to happen to prepare for breaking ground.

Before the casino building can start with architecture firm DSGW designing it, it was necessary to get approval from Shakopee Mdewakanton Sioux Community for a $29 million loan. The total project may end up costing $43 million. There is a slight concern with the loan repayment of 15 years at 6.5%, but there is a feasibility for the casino to earn $5.8 million per year. Plus over 200 jobs will be provided to Tribe members and local residents, which has helped get the project approved. Job preference will be given to Tribe members.

The tribe currently runs several small Class III gaming venues in the state including the Silver Wolf Casino in Wolf Point.

The Shakopee Mdewakanton Sioux Community own and operate the Mystic Lake Casino & Hotel in Prior Lake, Minnesota, Little Six Casino and a number of other enterprises.